Failsafe train vehicle control signal threshold detector apparatus
US4247790A · kind A · utility
8Cited by
6References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1976 |
| Grant date | Jan 27, 1981 |
| Priority date | — |
| Expiry date | Jan 22, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/7955
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A more failsafe signal voltage threshold determining apparatus is disclosed for operation in a train vehicle control system, and which utilizes the forward voltage drop characteristic of an input light emitting diode of an optical isolator device as a train vehicle control signal threshold reference. The detector transistor of the optical isolator device provides an output control signal in response to an input train vehicle control signal applied to the light emitting diode which has a voltage level high enough to overcome the light emitting diode voltage drop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.